With pet ownership at an all-time high, builders and developers are pulling out the stops to please residents of the four-legged variety

Mario Greco set out to accommodate five very particular residents when he built his 6,600-square-foot, Tudor-style house in Chicago. The house was oriented to maximize yard space, a system of internal doors keeps everyone in their own area and a custom-built washing station has heated stone floors.

"Pretty much any time a design issue came up it was, 'How is it going to work with the dogs?' " says architect Chris Walsh, adding that he consulted his dog-groomer brother-in-law for advice on how to best satisfy...